I heard about some beta version of SteamVR with Support for linux through Steam Link a while ago, but never got it to work under endeavour. ALVR came damn close. It was able to see my Quest 3 and SteamVR was running and detecting the headset + controllers too. Unfortunately never with any display output. I just hope Valve brings out some Headset based on SteamOS.
If you decide to buy a MacBook (and from my recent experience with an M1 Pro I would advise against it) you should check in advance if all your daily software is available. Asahi itself is fairly stable and enjoyable to use, the software repo is still lacking in a lot of places though. As others have said, you’ll probably be better off financially and mentally with a decently specced used Thinkpad if Linux is your primary OS.
Not quite. You can use your free apple ID for temporary self-signing. But this cert is only valid for 7 days and can sign up to 3 apps simultaneously before you have to update the cert.